Generally, vehicle lamp fixtures are structures in which a lens is installed to cover a front opening of a lamp housing, and a light bulb is arranged in a lamp space surrounded by the lamp housing and the lens. Then, in order to effectively use the light bulb, an aluminum film is vapor deposited so as to make the surface on the inside of the lamp housing act as the reflective surface of a reflector. In this case, an aluminum vapor deposition treatment is performed of coating an organic solvent-based acrylic paint on the inside of the lamp housing as an undercoating, following by vapor depositing aluminum, and further coating an organic solvent-based acrylic paint as a top coat in order to protect this vapor deposited surface so as to obtain a product with the surface on the inside of the lamp housing as the reflection surface of a reflector and having a diffuse reflectance of no more than 5%.
In recent years, an abbreviation of undercoat treatment process (so-called direct vapor deposition) has been carried out due to problems of organic solvents impacting the environment, and rationalization by the simplification of the production process and the like. As characteristics of these lamp housings, they have been demanded to possess favorable surface gloss and diffuse reflectance, and in a case of the surface gloss and diffuse reflectance being favorable, the attraction as an automobile part will improve.
In addition, in the production of lamp housings, the continuous molding time tends to be longer for rationalization by simplification of the molding process, productivity improvements, etc. As a result, trouble occurs in that the surface gloss of lamp housings declines and the diffuse reflectance gradually rises, accompanying the adhesion and accumulation of volatile component included in the molding material of lamp housings onto the die.
For example, Patent Document 1 discloses it being possible to improve the poor appearance of molded articles by using a specific AES resin as the thermoplastic resin. Patent Document 2 discloses it being possible to improve the surface appearance during direct vapor deposition, by using a composition blending a specific antistatic agent into a rubber-reinforced resin using a specific rubber-like polymer. In addition, Patent Document 3 discloses it being possible to improve the surface appearance during direct vapor deposition by using an acrylic rubber-reinforced resin using an acrylic rubber arrived at by polymerizing with a specific emulsifier.
However, the surface appearance during direct vapor deposition when performing continuous molding is in no way disclosed in any of the Patent Documents. As a result, in the molded articles obtained during continuous molding, a thermoplastic resin having diffuse reflectance that is superior when performing direct vapor deposition still does not exist, and thus, a thermoplastic resin has been demanded that satisfies the above issues.    Patent Document 1: Japanese Unexamined Patent Application, Publication No. 2004-352842    Patent Document 2: Japanese Unexamined Patent Application, Publication No. 2009-155421    Patent Document 3: Japanese Unexamined Patent Application, Publication No. 2006-131677